Abstract 3535: Strong Human Tissue-Engineered Blood Vessels: Cultured in Weeks instead of Months
Objectives: The aim of this study was to show the feasibility of culturing strong human tissue-engineered (TE) small diameter blood vessels in a short culture period. These vessels can ultimately be used for coronary artery bypass grafting (CABG). So far, the culture of strong human TE blood vessels required long culture times, up to several months, either or not combined with telomerase gene therapy. Combining a compound fast-degrading scaffold with strain-based mechanical conditioning, we present strong, living, human TE blood vessels after 28d of in-vitro culture.
Methods: Small-diameter blood vessels (ID=3mm) were engineered from biodegradable scaffolds and seeded using fibrin as a cell carrier with myofibroblasts isolated from discarded saphenous veins from 2 patients undergoing CABG (47 and 65 years). The vessels were subjected to dynamic strain conditions and cultured for 28d. The newly formed vessels were analyzed as to microstructure, extracellular matrix composition and mechanical properties. In addition, they were compared to human left internal mammary arteries and saphenous veins, the standard grafts used in CABG.
Results: TE blood vessels (n=8) displayed equal cell densities compared to native vessels and contained 50% of the native collagen content. After the culture period, the fast-degrading scaffold did not contribute to the mechanical integrity of the constructs. The TE vessels demonstrated burst pressures of 903±123mmHg. The mechanical properties of the TE vessels in the physiologically relevant range, assessed by tensile testing, were similar to those of native arteries.
Conclusions: In this study we present the strongest human TE blood vessels in a 28d-culture period, in which the scaffold does not contribute to the mechanical properties. Animal studies are planned to investigate in-vivo functionality.